I usually make all malt beers, though I use Oatmeal or Cornmeal in some recipes to get the style I want, but You can just add more extract (or more grain) if you want to make a bigger beer. I don't usually use purified sugars in my beer, but my buddy that brews Belgian beers uses quite a bit of sugar to raise the ABV without increasing the FG.

Most of the beers I prefer are in the lower ABV range, but I occasionally make a 6-7% beer and I've made a 9-10% beer a couple times. I just use the amount of grain needed to make the beer with the gravity and ABV that I want.

Malto-dextrine is a special case. It is a non-fermentable carbohydrate, so it is added to increase body and won't increase the % alcohol. So, you might want to reconsider that addition.